Single-rod gear shifting system for a manual gearbox for a motor vehicles

ABSTRACT

The invention relates to a gear shifting device ( 2 ) comprising a single-rod gear shifting system in a housing of a motor vehicle manual gearbox. Said device comprises a central gearshift shaft ( 32 ) and fork-type gear shifting elements in the form of gear shifting swinging forks or gear shifting forks ( 4, 6, 8, 10 ) which are optionally and individually engaged with the gearshift shaft ( 32 ) by rotating the same ( 32 ), and which carry out a gear shift of the selected gear shifting element by means of displacement of the gearshift shaft ( 32 ) along a rotational axis ( 34 ) of said gearshift shaft ( 32 ). Said gear shifting device ( 2 ) comprises a first element ( 58, 60 ) which is connected to the gearshift shaft ( 32 ) and which co-operates with a second element ( 62 ) fixed in the housing, in order to define the rotation of the gearshift shaft ( 32 ). The second element ( 32 ) fixed in the housing comprises a number of slits ( 66 ) of a defined width, corresponding to the number of gear shifting passages, said slits co-operating with two pins ( 58, 60 ) which are arranged on the gearshift shaft ( 32 ) and which form the first element. Each one of said pins ( 58, 60 ) engages in the slit ( 66 ) corresponding to the respective gear shifting passage during the rotation of the gearshift shaft ( 32 ), when one of the gear steps is positioned in the selected gear shifting passage.

[0001] The present invention concerns a one-shaft switching device forvehicle manual shaft gearboxes in particular for six-gear transmissionswith a central disengaging shaft and with fork-like switching elementsin the form of shifting arms or idlers that engage in sliding sleevesaccording to the principal clause of claim 1.

[0002] A one-shaft switching device for a vehicle manual shift gearboxwith fork-like shifting arms engaging in sliding sleeves that is knownfrom the Applicant's DE-A 199 51 683 which can be pivoted, via at leastone disengaging shaft, around parallel pivot bearings from its neutralposition into shifting positions, whereby stationary locking devices inthe gearbox housing are equipped with locking grooves in the form oflocking shifting arms fastened to the shifting arms and cooperate insuch a way that the remaining shifting arms remain locked in theirneutral position if one shifting arm is pivoted into a gear position, isknown from the Applicant's DE-A 199 51 683. The disengaging shaftpositioned parallel to the wheel set actuates the shifting forks or theshifting arms when the gears are shifted. The gear to be shifted isselected when the switching finger of the disengaging shaft is locatedin a carrier of the switching fork or the shifting arm to be shifted. Ifa gear is shifted, the shift fingers of the neighboring shifting forksor shifting arms that are not shifted are located below or above thecarriers of the shifting fork or the shifting arms. The potentialshifting latitude results from the clearance of the shift finger and thecarriers of the non-shifted gears. Chamfers at the shift finger of thedisengaging shaft and at the carriers of the shifting forks and theshifting arms determine the schematic at the gearshift.

[0003] In addition, a switchgear with a disengaging shaft is known fromDE-A 198 59 482 that is held in a sliding position in the axialdirection and pivotally in its circumferential direction and is equippedwith a lever. A plurality of carriers connected with the shifting armsor shifting forks are arranged so as to slide in the axial direction onthe disengaging shaft. The disengaging shaft is rotated in thecircumferential direction with an actuation lever connected to thedisengaging shaft in order to engage the lever at the disengaging shaft,if so desired, with one of the carriers. The disengaging shaft can bemoved by the actuation lever in order to move the engaged carrier bymeans of the lever at the disengaging shaft, so that such an actuationof the disengaging shaft shifts the gears. Located on the disengagingshaft, a first element cooperates with a second element that is fastenedon the housing. A groove is provided in one of the elements, which isengaged with the other element in such a way that the movement of thedisengaging shaft is defined by the selected direction. The necessarycomponent expenditure for the formation of such a setting is great.Furthermore, an additional array of elements must be provided at thedisengaging shaft that has an effect on the length of the disengagingshaft.

[0004] The invention is based on the task to provide a switchgear with asetting for the definition of a selected movement that avoids theexisting disadvantages.

[0005] This goal is achieved by means of a switchgear with thecharacteristics of claim 1. Embodiments are the object of the dependentclaims.

[0006] A switchgear with a one-shaft switching device is located in ahousing of the vehicle manual shift gearbox. The switching devicecomprises a central disengaging shaft and fork-like switching elementsin the form of shifting arms or idlers, which selectively andindividually engage the disengaging shaft through the rotation of thedisengaging shaft and which perform a gear shift of the selectedswitching element by pushing the disengaging shaft along the rotatingaxis of the disengaging shaft. The switching device is provided with afirst element connected with the disengaging shaft, that cooperates witha second element fastened on the housing, in order to define therotating of the disengaging shaft. The second element that is fastenedin the housing is equipped with slots of a defined width, whereby thenumber of the slots corresponds to the number of shifting latitude pathsthat cooperate with two pins located on the disengaging shaft andforming the first element. One of the pins engages in the appropriateslot that corresponds to the respective shifting latitude path when thedisengaging shaft is turned and that lies opposite to the pins after thedisengaging shaft has turned when the gear is shifted into a gear levellocated in the selected shifting latitude paths. In a preferredembodiment, the pins are located on a shift finger with which one of thefork-like switching elements can be moved in order to shift gears.Therefore, the pins are located on the same shift finger that is,otherwise, used for shifting into a gear level. With an appropriaterotation of the disengaging shaft, the slit in which the pins engagecorresponds to the shifting latitude path in which those gear levels arelocated that are used for the shifting process by the switching elementwhereby the shift finger engages in the appropriate shifting fork orshifting arm. In one embodiment, a groove whose length essentiallycorresponds to the length of the slots in the second element is locatedbetween the two pins. Thus, the axial length of the two elements is keptshort and the distance between the pins and the slots is short. In oneembodiment, the groove between the two pins cooperates with the carrierlocated at the fork-like switching element in order to shift gears. Inone embodiment, the two pins are located on a slide that is attached tothe switch finger. Advantageously, the pins are formed as teeth or camsand the slits are equipped with repulsion slats. The axial expansion ofthe first and second element, along the rotating axis of the disengagingshaft, is determined by the length of the slots plus the length of thetwo pins. The length of the slots corresponds to the covered shiftingtravel of the disengaging shaft. The axial construction length canthereby be shortened, relative to existing systems. As a pin is locatedat each end of the slot, the axial construction length of the system,consisting of a first and a second element, is no longer determined bythe length of the switching latitude path, as the element that can bemoved with the disengaging shaft does not have to be moved from one endof the switching latitude path to the opposite end of the same or aneighboring switching latitude path. According to the invention, insteadthe other pin engages in this slot or in a neighboring slot immediatelyafter one pin has left the slot. Thus, the design of the shiftinglatitude path can be made more exact. The selected clearance in theswitchgear is almost completely minimized. The diagonal switchingcapability in the transmission, i.e., the possibility to shift easilyand comfortably from one switching latitude path to a neighboringswitching latitude path, is improved and the shifting comfort issignificantly increased. The fulfillment of the comfort requirementsgoes hand-in-hand with a simultaneous cost reduction. The function ofthe shift finger at the disengaging shaft and the carriers at theshifting fork or shifting arms is returned and reduced to the originalfunction, which is the shifting process of the selected shifting fork orshifting arm. The contours of the shift finger and the carriers nolonger determine the schematic; their tolerances can be designed moreroughly, leading to significant cost savings. The result is a highshifting security because the setting-like cooperation of pins and slotsfacilitates an early shifting latitude rejection, thus avoiding theclassical locking process that constitutes the simultaneous actuation oftwo shifting forks or shifting arms up to the locking of one shiftingfork or shifting arm. The element equipped with the slots is fastened tothe housing and is bolted together or pinned to the transmissionhousing. Repulsion slants and the selected clearance are defined in thiselement at the slots. The selected clearance is transmitted to thedisengaging shaft by the pins or cams connected to the disengagingshaft, which are also called single-track cams or contour cams. One pinor cam is located in front of the slots, and another behind the slots.Thus, a double mapping of the shifting latitude path is no longernecessary.

[0007] The invention is explained in greater detail by means of thedrawings. They show:

[0008]FIG. 1 is a switching device;

[0009]FIG. 2 is a cut-out of a switching device with elements forclearance selection; and

[0010]FIG. 3 is a changed embodiment according to FIG. 2.

[0011] A switching device 2 has four shifting arms 4, 6, 8, 10 that arelocated pivotally around the swivel axes 12, 14, 16, 18 in atransmission housing that is not shown in detail. The shifting arms 4,6, 8, 10 are designed in the form of forks and are equipped with bearingholes 20, 22, 24, 26 in the area of the fork-like ends where slidingblocks 28 are located pivotally, said sliding blocks being located inthe circumferential grooves of switching sleeves belonging to thecouplings. The couplings (not shown in detail) rotate around a rotatingaxis 30. Parallel to the rotating axis 30 and perpendicular to theswivel axes 12, 14, 16, 18, a selection and disengaging shaft 32 islocated that can be rotated in the transmission housing around arotating axis 34 in a rotating direction 36 and that can be axiallymoved in a switching direction 38. Shift fingers 40, 42, 44, 46 arefastened on the selection and disengaging shaft 32 and arranged at anangle to each other.

[0012] The shift fingers 40, 42, 44, 46 engage individually andsequentially with fork-like carriers 48, 50, 52, 54 that are fastened onthe shifting arms 4, 6, 8, 10 during a rotational movement of theselection and disengaging shaft 32. The shifting arms 4, 6, 8, 10 andthe shift arms 40, 42, 44, 46 are each allocated to individual gears.For example, the shifting arm 4 is allocated to the reverse gear, theshifting arm 6 is allocated to the first and second gear, the shiftingarm 8 is allocated to the third and fourth gear, and the shifting arm 10is allocated to the fifth and sixth gear.

[0013] The switching device 2 is shown in a neutral shifting position,whereby the selection and disengaging shaft 32 is rotated in such a waythat the shift finger 44 engages with the carrier 52. If the selectionand disengaging shaft 32 is moved toward one of the two shiftingpositions 38, the third or fourth gear is shifted, whereby thecorresponding coupling is set via the shifting fork 8 and thecorresponding sliding blocks. In the shifting position, the shiftingfork 8 can be arrested via an arresting groves 70, whereby an arrestingbolt 72 engages with the arresting groove 70. The selection anddisengaging shaft 32 is rotated and axially moved via a system of rods(not shown in detail).

[0014] A slide 56 is equipped with two single-track cams 58 and 60,which is located on the shift finger 46. This part of the switchingdevice 2 is summarily explained in greater detail in FIG. 2.

[0015]FIG. 2 shows the shift finger 46 on the disengaging shaft 32carrying the slide 56. The shift finger 46 can engage with the fork-likecarrier 54 at the shifting fork 10 through the appropriate rotation ofthe disengaging shaft 32, whereby the fifth or the sixth gear is shiftedthrough the axial movement of the disengaging shaft 32 in the shiftingdirection 38. In the neutral position of the switchgear 2 as shown, thefirst single-track cam 58 is on one side of the setting element 62 thatis fastened to the transmission housing by means of bolts 64. Slots 66,whose number corresponds to the number of shifting latitude paths, areincorporated in a setting element 62. On the side of the setting element62, opposite to the single-track cam 58, the single-track cam 60 isprovided on the slide 56. A groove 68 between the single-track cam 58and 60 essentially corresponds to the length of the slots 66. Thesingle-track cams 58 and 60 are equipped with slants that can engagewith slants 74 at the slots 66.

[0016] A changed embodiment is depicted in FIG. 3. In this embodiment,the shift finger 46 is designed in such a way that it is equippeddirectly with the single-track cams 58 and 60. The groove 68 between thetwo single-track cams 58 and 60 can be engaged with the carriers 54which, in this embodiment, take the form of cams, at the shifting fork10 after the appropriate rotation of the disengaging shaft 32, wherebythe fifth or sixth gear is shifted through the axial movement of thedisengaging shaft 32 in the shifting direction 38. The setting element62 with the slots 66 is fastened to the transmission house (the methodis not shown). The groove 68 between the single-track cams 58 and 60essentially corresponds to the length of the slots 66.

Reference Numerals

[0017]2 switching device

[0018]4 shifting arm

[0019]6 shifting arm

[0020]8 shifting arm

[0021]10 shifting arm

[0022]12 swivel axis

[0023]14 swivel axis

[0024]16 swivel axis

[0025]18 swivel axis

[0026]20 bearing hole

[0027]22 bearing hole

[0028]24 bearing hole

[0029]26 bearing hole

[0030]28 sliding block

[0031]30 rotating axis

[0032]32 selection and disengaging shaft

[0033]34 rotating axis

[0034]36 rotational direction

[0035]38 shifting direction

[0036]40 shift finger

[0037]42 shift finger

[0038]44 shift finger

[0039]46 shift finger

[0040]48 carrier

[0041]50 carrier

[0042]52 carrier

[0043]54 carrier

[0044]56 slide

[0045]58 single-track cam

[0046]60 single-track cam

[0047]62 setting element

[0048]64 bolting

[0049]66 slot

[0050]68 groove

[0051]70 arresting groove

[0052]72 arresting bolt

[0053]74 slant

1-8. (canceled)
 9. A switchgear (2) with a one-shaft switching device inthe housing of a vehicle manual shift gearbox comprising a centraldisengaging shaft (32) and fork-like shifting elements in the form ofshifting arms or shifting forks (4, 6, 8, 10), which selectively andindividually engage with the disengaging shaft (32) through the rotationof the disengaging shaft (32) and which perform a gear shift of theselected shifting element through the movement of the disengaging shaft(32) along the rotating axis of the disengaging shaft (34) and where theswitching element (2) is equipped with a first element (58, 60)connected with the disengaging shaft (32) that cooperates with a secondelement (62) that is fastened on the housing to define the rotation ofthe disengaging shaft, wherein the second element (62) fastened on thehousing is equipped with slots (66) of defined width in a numbercorresponding to the number of shifting latitude paths that cooperatewith two pins (58, 60) located on the disengaging shaft (32), which formthe first element and where one of the pins (58, 60), when a gear levellocated in one of the selected shifting latitude paths is shifted,engages in the appropriate slot (66) that corresponds to the appropriateshifting latitude path when the disengaging shaft (32) is rotated: 10.The switchgear (2) according to claim 9, wherein the pins (58, 60) arelocated on a shift finger (46) with which one of the fork-like shiftingelements (10) can be moved for the shifting of gears.
 11. The switchgear(2) according to claim 9, wherein a groove (68) is provided between thetwo pins (58, 60) that essentially corresponds to the length of theslots (66) in the second element (62).
 12. The switchgear (2) accordingto claim 11, wherein the groove (68) between the two pins (58, 60) isworking together with one carrier (54) located on the fork-likeswitching element (10) to shift gears.
 13. The switchgear (2) accordingto claim 10, wherein the two pins (58, 60) are located on a slide (56)that is attached on the shift finger (46).
 14. The switchgear (2)according to claim 9, wherein the axial expansion of the first (58, 60)and the second element (62) along the rotating axis (34) of thedisengaging shaft (32) is essentially determined by the length of theslots (66) plus the length of the two pins (58, 60).
 15. The switchgear(2) according to claim 9, wherein that the pins (58, 60) are designed asteeth or cams.
 16. The switchgear (2) according to claim 9, wherein theslots (66) are equipped with repulsion slants (74).